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Pressure Decay Testing and Why It is Important in BSL-4 Laboratory Annual Verification Testing

July 26, 2023

What is Pressure Decay Testing?

Pressure decay testing is a systematic procedure to validate room construction to determine if the laboratory’s containment barrier defined by walls, floors, ceilings, penetrations, and other construction features meet the required integrity to prevent leakage of unfiltered air from the BSL-4 containment space. Pressure decay testing is the most reliable method to prove that a BSL-4 laboratory room’s envelope is airtight. The National Institutes of Health, which oversees the operation of the BSL-4 laboratories located in Fort Detrick, Maryland, and Hamilton, Montana, indicates that the standard BSL-4 pressure testing method is to negatively pressurize the room to 2 InH2O, and then measure the pressure decay. The requirement for a BSL-4 laboratory is to maintain a pressure higher than 1 InH2O after 20 minutes (Memarzadeh, 2009). This quantifiable test can pinpoint issues with critical equipment in a BSL-4 laboratory including:

Air distribution valves
Isolation dampers and actuators
Isolation dampers bioseals
APR doors gaskets
Barrier autoclaves gaskets and seals
Breathing air system lines
Laboratory vents

Why is Pressure Decay Testing Important?

Pressure decay testing provides an acceptable level of quality for annual verification testing of BSL-3 Ag and BSL-4 laboratories. The complex design and operation of these facilities minimize the potential risk of an aerosolized pathogen to staff, the general population, and the surrounding environment. The pressure decay test verifies that there is no air leakage. Air leakage can compromise research studies through cross-contamination of multiple pathogens.

How to Prepare for Pressure Decay Testing?

The following steps must occur before conducting a pressure decay test:

Verify the facility’s HVAC system is operational and commissioned.
Verify the building automation system (BAS) is operational.
Provisions for setting up testing equipment are available (pressure transducer enclosures, decontamination ports, etc.)
Use either testing vacuum pump or exhaust system to negatively pressurize the system up to 2.00 InH2O.
Check all potential sources of leakage for audible or identifiable leakage.
To the extent practical, eliminate/minimize potential sources of heat generation so that the space stays at a relatively constant temperature throughout the testing (lights, freezers, motors, etc.)
Isolate the affected areas from pressure fluctuations that will affect the testing.
Monitor room Differential Pressures (DP) with static conditions (no airflow or pressurization air) to ensure that there are no external effects that will invalidate the results.
All plumbing fixtures and floor drain traps are filled with water.
If previously identified, all construction deficiencies have been rectified and completed.
Ensure no visible damage is apparent to the room under test.
All conduit, wiring, and electrical boxes have been epoxy-sealed.
All epoxy coatings (if epoxy coatings are present) are in place and free of visible defects.
Seamless flooring is in place and free of visible defects.
Check valves and isolation valves are in place and operational.
Dunk tanks (if installed) are filled.
Autoclaves are operational and have their seal barriers in place.
APR doors are functional and interface to BAS, and door access control systems are operational.
Room temperatures are measured and data logged. Changes in temperature cause changes in pressure.
Atmospheric pressure is measured using an instrument with an accuracy of 0.01 In. Hg. which is equivalent to 33.86 Pa or .136 InH2O.
A pressure decay test form has been generated.
It has been confirmed that room and general laboratory conditions are acceptable for testing the laboratory.
The subject test area should be isolated and then allowed to stand for 20 minutes before commencing the test.

Acceptance Criteria

The room passes the pressure decay test if the residual pressure at the end of the 20-minute period is -1.00 InH2O or more negative (50% of the initial room’s pressure value) under steady state conditions for temperature and barometric pressure. Each pressure zone within maximum containment (BSL-4) must pass two consecutive pressure decay tests.

If Pressure Decay Testing Is Not Feasible

If annual pressure decay testing is not feasible for some rooms, then another option would be conducting a smoke saturation test. A smoke saturation test is a qualitative test, but it will help the users to identify possible issues with the containment envelope. The maximum containment engineering/maintenance team will need to command the laboratory into maintenance or decontamination mode. The surrounding areas will be more negative; therefore, if there is a leak or issue during the testing, the maximum containment team will be able to identify it. The challenge with this method is that it is only recommended if the rooms are decontaminated.

Another option (a little bit messy and more time-consuming) is the use of a soap solution on critical areas. This test is the least accurate option because it will only test perimeter barrier components. The laboratory will require decontamination prior to testing.

“Light Pressure Decay Test”

If there is a decontamination or maintenance mode for the facility, you can run what we call a “light pressure decay test.” Before a decontamination process begins, you need to make sure the laboratory is airtight. The light pressure decay test is typically conducted from the BAS for testing and running trends. No additional testing equipment is used. This is a non-invasive procedure.

What About BSL-3 Laboratories?

BSL-3 laboratories can be pressure decay tested depending on the laboratory’s envelope construction system, calculated room’s leakage rate, and room’s isolation capabilities. Pressure decay testing on BSL-3 laboratories is more challenging since, by concept, these types of laboratories are considered “leaky labs” (infiltration of air is required). However, with the implementation of good room isolation standard operating procedures, the pressure decay test can be achieved with no issues.

Recommendations

Pressure decay testing is a team effort. Our recommendations to have a successful pressure decay test include:

Make sure to get involved with experienced staff and a third-party consultant such as World BioHazTec from the beginning. Pressure decay testing is a critical testing procedure that requires experience and knowledge of BSL-4 and BSL-3 laboratories.
Pressure decay testing should not be rushed. It requires coordination and is a team effort that involves the biosafety officer, Responsible Official, Alternate Responsible Official, facility director, facility personnel, and contractors.
Differential pressure meters and test equipment calibration must be current and traceable to NIST.
Check and double-check items which could inadvertently affect the testing outcome.
If room or atmospheric conditions are not stable, such as a thunderstorm, do not hesitate to reschedule the test.

If you would like to learn more about pressure decay testing, contact World BioHazTec for a free consultation or send us an email.

Works Cited

Farhad Memarzadeh (2009, September 15). Pressure and Temperature Correction for BSL4-Pressure Decay Test. (O. o. National Institutes of Health, Producer) Retrieved 2023, from Pressure and Temperature Correction for BSL4-Pressure Decay Test: https://orf.od.nih.gov/TechnicalResources/Bioenvironmental/Documents/PressureandTemperatureCorrectionforBSL4_508.pdf

Featured Posts

Outsourcing Training for Work in Critical Environments

When managing a high-containment facility, such as a BSL-3 lab, safety is paramount. Training staff to handle biological hazards properly and operate within stringent protocols can literally be a matter of life and death. A critical question many organizations face is whether to develop training programs in-house or outsource this training to a specialized provider. We’ll explore barriers to in-house development and delivery of quality training and why outsourcing your training for high-consequence workplaces could be the best option for your organization. What are your barriers to faster learning design and development? A recent survey conducted by the Association for Talent Development (ATD), which has supported instructional developers of employee training programs worldwide for over 80 years, identified eight top barriers to faster learning design and development.[1] The top three barriers are: Adapted from DeFelice, R. 2021. ATD Blog. Rounding out the top eight barriers include lack of availability of Subject Matter Experts (SMEs) or stakeholders at 37%. In our experience, SMEs and stakeholders have many hats they wear, and their time is limited. Often, SMEs are outside of the organization and pose an additional expense to the development of in-house training, initially and annual updates to the curriculum. World BioHazTec uses the Successive Approximation Model (SAM) approach to instructional design. SAM is a three-phase process: Preparation Phase, Iterative Design Phase, and Iterative Development Phase.[2] SMEs and stakeholders are brought in at the initial outlining phase and then only as needed for review. Because this is an iterative process, by the time the final phase is reached, SMEs and stakeholders have agreed to the plans and there should be very few revisions, or scope creep, to the design and plans. This saves time for these busy professionals and reduces costs by managing time and scope. Limited learning infrastructure—such as access to dedicated systems, authoring tools, and networks—accounts for 35% of the barriers. Authoring tools and resources, such as licensed images, add to the expense. Additionally, online self-paced (asynchronous) learning modules require authoring tools to create interactive content with feedback, as well as a learning management system to deliver the modules effectively. The final three barriers are a lack of learning and development skills within the talent development team (25%), lack of accountability (when the talent development team or SMEs do not fulfill responsibilities or meet deadlines) (23%), and insufficient leadership or management support (19%). These barriers indicate that staff are often occupied with other duties, with training development frequently becoming a lower priority. How much extra time does your staff have? Developing in-house training programs takes time—far more than many organizations realize. According to ATD in its most recent survey, creating one hour of new classroom training can take anywhere from 112 to 367 hours to develop.[3] That means developing just a half-day session could consume weeks of work by several employees. Time that could be better spent on other critical functions of your lab. Also, think of the breadth of knowledge and skills required to operate and maintain a high-containment laboratory, both for inside and outside, from construction to cybersecurity, from environmental protection to personal safety. Biosafety professionals not only require training in performing their jobs safely, they are also involved in risk assessments and compliance with applicable regulations daily, and appropriate emergency response. Frequently, the biosafety professional is called upon to participate in the planning, design, and validation of a new biocontainment laboratory or renovation of an existing facility. “Biosafety professionals should have a foundation in all aspects of working in and around a high-containment laboratory and develop skills to ask questions in specific terms and have the confidence to question the answers.” -World BioHazTec Course Development Guide. [Internal Communication] Developing meaningful, high-quality training that addresses all necessary components typically requires more SMEs and stakeholders than a single facility may have available for training development. Outsourcing training development strengthens course quality by bringing together SMEs with various expertise for only the time that is necessary under the management of a proven training development team. Also, the development team can use resources already developed to tailor to the specific needs of your facility and staff, which saves time and resources. If you’re thinking of transitioning your existing training into an online format, the time investment can be even greater. Converting a course into effective web-based training requires expertise in instructional design, an investment in e-learning tools, an understanding of e-learning platforms, and the ability to ensure that virtual training still delivers the same level of engagement and effectiveness as in-person sessions. Just as with any training, online training and learning management systems must be monitored regularly and reports generated to stakeholders. Outsourcing this process to specialists not only saves your team countless hours but also ensures the training is designed by professionals with experience in biosafety, biosecurity, and online learning. A Fresh Perspective and Unbiased Assessment One of the key benefits of outsourcing your BSL-3 training is gaining access to an external team of experts who can offer a fresh perspective. When organizations develop their own training programs, there’s often a risk of becoming too close to the material, potentially missing gaps or risks that an SME might spot, offering a fresh perspective. An external provider can objectively assess your current protocols, highlight potential areas for improvement, and suggest best practices based on up-to-date industry standards. “Things change quickly …, so job responsibilities must evolve. If companies evolve their strategy and expect employees to expand their skill sets, offering a team continuous learning will help prevent them from falling behind.” [2] In high-stakes environments like BSL-3 labs, where even minor oversights can have serious consequences, having an unbiased third-party review can add an additional layer of safety. Expert consultants are experienced in tailoring their training programs to meet both your specific operational needs and strict regulatory requirements, ensuring your staff is fully equipped to handle emergencies and day-to-day challenges. CEUs and Professional Development Incentives Professional development is also a tool for employee retention. “About 80 percent of employees rank professional development and continuous learning as high priorities when job hunting. And 94 percent of employees say if an employer invested more in learning and development, they would stay longer at an organization.” [3] Another significant advantage of outsourcing BSL-3 training is the ability to offer Continuing Education Units (CEUs). If your training provider is accredited, they can award CEUs to participants which can be used to maintain certification with professional organizations. This ensures your team remains compliant with the latest industry developments and ongoing certification requirements. It also provides an added incentive for staff to engage in the training. CEUs enhance the perceived value of the training, as they provide tangible career benefits to employees. By outsourcing, you can integrate this offering into your program without the burden of navigating the lengthy accreditation process yourself. Outsourcing Offers Expertise, Efficiency, and Compliance The decision to outsource BSL-3 training boils down to efficiency and safety. By partnering with an experienced external provider, you’re investing in expert insights, saving substantial time, and ensuring your team has access to accredited, top-tier training. Not only does this free up your internal resources, but it also offers peace of mind knowing your staff is receiving the most current and comprehensive training available. So, should you outsource your BSL-3 training? For most organizations, the answer is a resounding yes. World BioHazTec provides extensive professional development training. Schedule a free consultation to learn more about our customized training offerings. [1] DeFelice, R. 2021. ATD Blog. Retrieved from https://www.td.org/content/atd-blog/how-long-does-it-take-to-develop-training-new-question-new-answers [2] Allen, M. (2012). Leaving ADDIE for SAM – An agile model for developing the best learning experiences. Washington DC: American Society for Training and Development. [3] Based on survey average module length of 23 minutes, the variance was 43 to 141 hours with an average of 67 hours. These results were used to calculate times to develop a one-hour module. [4] Rozensweig, F. 2022. Retrieved from https://www.td.org/atd-blog/shift-from-onboarding-to-everboarding. [5] Rosenzweig, F. 2022. ATD blog. Retrieved from https://www.td.org/content/atd-blog/shift-from-onboarding-to-everboarding

scientist using a pipette in a BSL-3 facility

The 5 Strategic Advantages of Certifying Your BSL-3 Facility

Biosafety Level 3 (BSL-3) incidents are rare, yet their repercussions are monumental. Operating at BSL-3 demands meticulous protocols and unwavering risk mitigation. While rare, any lapses can have far-reaching and potentially devastating consequences. In this article, we explore the significance of BSL-3 certification. Even though it may not be mandatory in your country, it proves to be a vital strategic move. 1. Professional Accountability In a Biosafety Level 3 (BSL-3) facility, professional accountability emerges as the first compelling intention. Activities in a BSL-3 facility include the propagation of high-risk pathogens and long-term storage. This entails a profound responsibility. Researchers operating within BSL-3 facilities are accountable for ensuring not only their safety but also the safety of their colleagues, the community, and the environment. Certification acts as a tangible manifestation of this commitment, demonstrating to stakeholders and regulatory bodies that the organization embraces the gravity of their work. Beyond biosafety, BSL-3 certification also underscores the importance of stringent biosecurity measures, ensuring the safeguarding of these pathogens against unauthorized access and potential misuse. By obtaining BSL-3 certification, operators signal their dedication to maintaining the highest standards of both biosafety and biosecurity, fostering a culture of responsibility and accountability within the facility and beyond. 2. Public Health Preparedness Biosafety Level 3 (BSL-3) facilities play an indispensable role in public health preparedness. When a pandemic strikes, BSL-3 facilities stand at the forefront of the fight, equipped with the expertise and infrastructure necessary to handle and analyze high-risk pathogens. These facilities serve as vital hubs for research, diagnostics, and the development of therapeutic interventions. BSL-3 certification, in this context, becomes a strategic asset, signifying a commitment to being at the forefront of global health emergencies. It positions the facility to swiftly and effectively respond to emerging threats, contributing significantly to public health resilience and preparedness on a global scale. When the real test of a pandemic arrives, a certified BSL-3 laboratory signifies a prepared laboratory, with competent professionals adeptly executing their roles, ensuring a prompt and effective response to safeguard public health. 3. Creating a Safe and Secure Culture In a certified BSL-3 facility, a dedicated commitment to establishing a culture of biosafety and biosecurity is evident. This certification stands as a tangible testament to the management’s unwavering dedication to continuously enhancing biosafety and biosecurity measures. It mirrors a proactive approach towards nurturing a workplace culture that places the well-being of its staff and the integrity of its operations at the forefront. The certification process mandates rigorous adherence to standards, promoting continuous training and evaluation. This level of commitment resonates with the laboratory personnel, instilling confidence that their management is wholeheartedly invested in cultivating an environment where biosafety and biosecurity take precedence. 4. Safety Equals Quality A certified BSL-3 facility not only prioritizes safety and security but also indirectly contributes to the overall quality of results. Taking reference from the World Health Organization’s Handbook on Laboratory Quality Management System, laboratory safety is a cornerstone for establishing robust laboratory practices. By fostering a culture of strict adherence to biosafety protocols, certified BSL-3 facilities systematically integrate quality management principles into their daily operations. This meticulous approach not only safeguards the well-being of personnel but also ensures the integrity of laboratory processes. As safety practices become ingrained in the laboratory’s ethos following international quality management principles, the probability of errors and contamination diminishes, leading to consistently high-quality research outcomes. In essence, the commitment to safety in a certified BSL-3 facility reinforces the crucial connection between safety practices and the reliability of scientific results. 5. International Collaboration Opportunities A certified BSL-3 facility, known for its adherence to rigorous safety and security standards, builds credibility and trust within the scientific community. Collaborators and funding agencies, especially those from different countries, are more likely to engage with a facility that is recognized for its commitment to maintaining high-quality, safe, and secure research environments. BSL-3 facilities that demonstrate adherence to internationally recognized certification standards also make themselves attractive partners for collaborations assuring that research will be conducted in a secure environment, minimizing the likelihood of accidents or incidents. Conclusion In the pursuit of scientific excellence, BSL-3 certification emerges not merely as a commitment to safety but as a strategic gateway to collaborative possibilities. A certified BSL-3 facility, fortified by rigorous safety and security standards, amplifies credibility within the scientific community and encourages collaboration on a global scale. Let World BioHazTec be your strategic partner in preparing your facility to meet our certification requirements, widely acknowledged as the gold standard in BSL-3 certification. Contact World BioHazTec (WBHT) to schedule a free 30-minute consultation or send us an email. You are a conversation away from starting down a successful pathway to meet BSL-3 facility compliance.

female scientist working with a petri dish

Five Design Considerations for Animal Laboratories

At the beginning of the design process, there are many decisions that must be made regarding equipment, sinks, showers, biological safety cabinets (BSCs), and other primary barrier equipment, the configuration of the HVAC system, and contingencies based upon the facility design elements required by the agents that will be worked with or studied. Sustainability, maintainability, and energy usage must also be factored into the design. Organizational preferred operations must be included, and SOPs often dictate final designs. Spatial relationships need to be evaluated to determine flow and function. When animals are part of the laboratory work, additional design features are needed which add complexity to the design. 1. Design Standards, Guidelines, and Regulations for Animal Laboratories Paramount to safety is the understanding of the application and intent of biosafety and biocontainment guidelines. Biosafety design is based upon risk assessment. The design team should be accustomed to working with the Biosafety Officer, users, and stakeholders in formulating and documenting risk assessments when needed to support design decision-making. Determining your research goals or planned laboratory work, grant design requirements, and regulatory compliance will drive the design criteria. When designing an animal facility such as an ABSL-2 or ABSL-3 laboratory, beyond the compulsory local national and international guidance documents, you may want to also consider the following guidelines and standards: NIH Design Requirements Manual for Biocontainment Laboratories; U.S. Department of Agriculture (USDA) Research Service Guidelines, (as applicable); Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC); National Research Council Guide for the Care and Use of Laboratory Animals; National Research Council Occupational Health and Safety in the Care and Use of Research Animals; and National Research Council Occupational Health and Safety in the Care and Use of Nonhuman Primates. 2. Odor The management of odor from animal facilities, autoclaving, waste treatment, and tissue digesters is unique to containment facilities. Elevator shafts and loading docks serve as pathways for the distribution of odors. Using positive pressured elevator vestibules, adjoining positive pressured corridors, and local ventilation can contain odors. Dedicating an elevator for vertical movement of animals from receiving to the animal suite will also control odors. Adding a pneumatic waste removal system can contain waste removal odors from the animal suite to the building loading dock area. These engineering controls allow for the placement of vivariums anywhere vertically in a research tower instead of the traditional basement location. 3. Noise Subjecting animals to noise and vibration can have significant impact on animal reproduction and sensory development, behavior, and can expose animals to injury startle responses. The location of rotating machinery in animal facilities can stress animals, so cage washing areas and mechanical spaces with fans and pumps need to be distanced from animal holding areas. Another source of noise is the ventilation system with elevated room level supply and exhaust noise. In addition to negatively affecting animals, this can also affect workers’ communication and awareness to their surroundings. 4. Space Requirements Caging design, rack sizes and types, and animal model are key factors in analyzing space requirements. Identifying the maximum number of types of animals to be housed according to biosafety level can maximize space utilization for the present and the future. This information bears heavily on the design approach to room space allocation, cage washing equipment, whether disposable caging is more economical, cage changing stations or BSCs, and watering system versus bottle caging. 5. Emergency Signaling Systems Placement of emergency signaling systems (e.g., fire alarm, HVAC failure alarm, room pressurization alarm, security alarm) is essential to alert personnel to act. Signaling systems must be accessible for lab personnel, biosafety officers, and emergency response personnel. Ever conscious of animals, the alarms cannot be strobing in holding facilities so as not to stress animals. Animal Laboratory Design Recommendations In analyzing the final design, emphasis needs to be placed on the details. Constant referral to the research program requirements, containment guidelines, lessons learned, project construction and operating budgets, and the completeness of the design documents are essential to a successful design that meets the users’ and the stakeholders’ needs and provides sustainability. Efforts spent in design by an integrated team of users, professionals, and stakeholders will culminate in a safe, sustainable, efficient, and secure research facility. Are you planning to build or renovate a BSL-3/ABSL-3 laboratory? No matter what project phase you are in, contact World BioHazTec (WBHT) to schedule a free 30-minute consultation or send us an email. We can prepare a feasibility study, develop conceptual designs with cost estimates, perform a site assessment, peer review design documents, commission/certify your animal facility, and train staff. You are a conversation away from starting down a successful pathway to meet containment compliance and sustainability.